KIEV (Reuters) - Ukraine’s largest lender, PrivatBank, said on Thursday Ukrainian law enforcement officers were conducting a “planned” search of its offices as part of an ongoing anti-corruption investigation.

The logo of PrivatBank is on display on the facade of a building outside the company's branch in Kiev, Ukraine, February 14, 2017. REUTERS/Gleb Garanich

Privatbank, Ukraine’s largest lender, was taken under state control with the backing of the International Monetary Fund in December after risky lending practices left it with a capital shortfall of more than $5.5 billion.

At the time the central bank estimated that 97 percent of its corporate loans had gone to companies linked to its shareholders, who include powerful tycoon Ihor Kolomoisky, Ukraine’s second-richest man.

The bank said on Thursday that Ukraine’s National Anti-Corruption Bureau (NABU) was conducting a “careful analysis of the ‘toxic portfolio’ of loans of previous owners of the bank” at its head office in the city of Dnipro, 400 km (248 miles) south-east of Kiev.

“As part of criminal proceedings to investigate the facts of illegal lending by previous owners and top managers, the bank is working with NABU to conduct planned work,” it said in a statement, adding that the work last for several days.

Ukraine started legal action to recover the loans made by PrivatBank on Monday.